Spring-chuck.



W. M. MOSBLEY.

SPRING CHUCK.

APPLICATION FILED No.1, 1911.

1,086,393. Patented Feb. 1o, 1914.

ZE/f

UNITED STATES PATENT OFFICE.

WILLIAM IVI. MOSELEY, OF ELG-IN, ILLINOIS.

SPRING-CHUCK.

1o all whom it may concern.'

Be it known that I, IVILLIAM M. Mesurer, a citizen of the United States,and a resident of Elgin, in the county of Kane and State of Illinois,have invented certain new and useful Improvements in Spring'- Chucks;and I do hereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawings,and to the characters of reference marked thereon, which form a part ofthis specification.

This invention relates to improvements in that class of spring jawchucks used in lathes, milling machines, screw machines, etc., wiichwhile differing somewhat in form yet in general are slotted to formspring jaws adapted for movement either inward or outward against thework to hold or clamp the work which may be placed wit-hin the chuck, orwhich may be placed over the same, the said jaws of the chuck beingactuated to effect the clamping or holding action thereof on the work bysuitable parts on the machine which coperate with said jaws in the actof tightening the chuck on the work.

The object of the invention is to provide improvements in chucks of thisclass designed to increase the flexibility of the jaws without weakeningthe same, and without changing the condition of the bearing contact ofthe chuck upon either the work or the lathe spindle by which the chuckis held, so as to better adapt the chuck for the work it has to perform,as more fully explained hereafter.

This invention consists in the matters hereinafter set forth and moreparticularly pointed out in the appended claims.

In the drawings z-Figure 1 is a side elevation of a chuck embodying myinvention. Fig. 2 is a transverse section on the line 2 2 of Fig. 1.Fig. 8 is a side elevation of a slightly modified form of chuck. Fig. 4cis a transverse section on the line el 4 of Fig. 3. Fig. 5 is lan endView of tie chuck.

As shown in the drawings the chuck comprises a body portion 10, which isas .shown made cylindrical, a head 11 at one end of the body and ascrew-threaded portion 12 at the other end of the body. Said chuck has alongitudinal bore 111 to receive the work to be held thereby, which asherein shown is an axial bore. As herein shown, said bore maySpecification of Letters Patent.

Application led December 1, 1911.

Patented Feb. 10, 1914. Serial No. 663,185.

be formed by making the chuck tubular from end to end, with the frontend of the bore of reduced diameter to constitute the bearing portion ofthe chuck. This form Iof the bore permits the work to be introducedthrough the rear end of the chuck, as well as from the front endthereof.

The chuck body and headare longitudinally slotted at angular-ly spacedpoints 15 from a point near the rear end of the chuck body outwardly toand through the front face 15 of the head. The slots 15 extend radiallyto the bore 14E and provide a plurality of spring jaws 16, 16 whichpermit the free or headed ends of the jaws to be closed inwardly uponthe work that is inserted into the axial bore.

The head is eXteriorly enlarged or made flaring to engage the mouth ofthe ordinary hollow lathe spindle, when the chuck is drawn backwardlyinto the spindle by the action of the usual draw-in spindle or othermeans, as is common in lathes of this type: the engagement of saidflaring surface of the head against the mouth of the hollow spindle,when the chuck is drawn into said spindle, causing the jaws to be closedupon the work and to clamp the same. The liaring` outline of the head 11of the chuck shown in Figs. 1 and 2 is a concave, curved line 17, whilethe outline of the head 11 of the chuck shown in Figs. 3 and 4, isconical as indicated at 18, but the particular contour of the head isnot material.

The chuck body is provided near its rear end with a slot 2O to receivethe usual pin carried by the hollow spindle, by which to non-rotativelylock the chuck in the spindle, while permitting relative endwisemovement of the chuck and lathe spindle in the act of tightening thechuck on the work.

In accordance with my invention I increase the radial andcircumferential iiexibility of the chuck by providing the Shanks of thejaws thereof, and between the slots 15, with auxiliary slots 22, 22,which are made shorter than the slots 15. Said auxiliary slots extendinwardly to the bore 111 of the chuck, as do the main slots 15. Theyterminate at their rear ends short of the rear end of the body of thechuck and stop at their front ends short of the front ends of the mainslots 15. These auxiliary slots, while not impairing the necessarylongitudinal tensile strength of the chuck, afford a circumferential andradial flexibility and resiliency to the jaws not found in the ordinarychuck. By reason of the fact that said auxiliary slots do not extend tothe outer face of the chuck head, neither the contacting surface of thechuck jaws with the work nor of the jaws with the lathe spindle ischanged, and, while said auxiliary slots give to the chuck, as a whole,greater radial and circumferential elasticity and resiliency, the headis not thereby weakened. The clamping action of the jaws, when closingupon the work in the chuck, takes place more nearly at the bases 23 ofthe jaws, which tends to cause the jaws to close on a longer radius thanif the Shanks of the jaws were unslotted, thus causing the sides of thebore to close more uniformly parallel upon the work, therebyfacilitating the true seating of the work in the chuck. By reason of theincreased resiliency and flexibility of the jaws, due to the auxiliaryslots, there is also less liability of the jaws breaking, and also lessliability of permanent setting of the jaws, particularly in cases wherethe chuck is being strained to hold work which is either larger orsmaller than its, normal capacity.

My improvements are adapted also to spring chucks wherein the jaws areforced outwardly against the work which inclose or partially inclose thechuck, and may be applied to chucks of both types of specificallydifferent structural details from that herein shown.

l claim as my invention z- 1. A hollow spring chuck provided at one endwith a head and at its other end with means for drawino the chuckendwise, said body and head being slotted longitudinally from theirfront faces rearwardly to a point short of the rear end of the body toprovide an odd number of spring jaws, said jaws being each provided withan auxiliary slot which extends from a point in rear of the front faceor head of the chuck rearwardly through the shanks of the jaws and whichterminate short of the rear end of the said chuck, the main andauxiliary slots extending radially to the bore of the chuck.

2. A hollow spring chuck comprising a body having at one end anexteriorly flaring head and at its other end a screw-thread,

the bore of the chuck extending from end to end of the chuck and beingdecreased in diameter' at the head, said chuck being provided with threeangularly spaced, longi tudinal slots which extend partially through thelength of the body and through the head to constitute three spring jawshaving three point bearing at the head, and said jaws being providedwith auxiliary, longitudinal slots which terminate at their outer endsshort of the ends of the first slots and at their inner ends short ofthe said screw thread.

In testimony, that I claim the foregoing as my invention I aflix mysignature in the presence of two witnesses, this 27th day of November A.D. 1911.

WILLIAM M. MOSELEY.

l/Vitnesses G. E. DowLn, HARRY S. GAITHER.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents. Washington, D. C.

